Although the 802.16 family of standards is officially called WirelessMAN in IEEE, it has been commercialized under the name "WiMAX" (from "Worldwide Interoperability for Microwave Access") by the WiMAX Forum industry alliance. The Forum promotes and certifies compatibility and interoperability of products based on the IEEE 802.16 standards.

The 802.16e-2005 amendment version was announced as being deployed around the world in 2009.[1] The version IEEE 802.16-2009 was amended by IEEE 802.16j-2009.

IEEE Recommended Practice for Local and metropolitan area networksCoexistence of Fixed Broadband Wireless Access Systems
(Maintenance and rollup of 802.16.2–2001 and P802.16.2a)
Released on 2004-March-17.

IEEE Standard for Local and Metropolitan Area Networks: Media Access Control (MAC) BridgesAmendment 2: Bridging of IEEE 802.16
(An amendment to IEEE 802.1D)
Released on 2007-August-14.

Current

802.16g-2007

Management Plane Procedures and Services

Superseded

P802.16i

Mobile Management Information Base
(Project merged into 802.16-2009)

Merged

802.16-2009

Air Interface for Fixed and Mobile Broadband Wireless Access System
(rollup of 802.16–2004, 802.16-2004/Cor 1, 802.16e, 802.16f, 802.16g and P802.16i)

Superseded

802.16j-2009

Multihop relay

Superseded

802.16h-2010

Improved Coexistence Mechanisms for License-Exempt Operation

Superseded

802.16m-2011

Advanced Air Interface with data rates of 100 Mbit/s mobile and 1 Gbit/s fixed.
Also known as Mobile WiMAX Release 2 or WirelessMAN-Advanced.
Aiming at fulfilling the ITU-R IMT-Advanced requirements on 4G systems.

IEEE Standard for Air Interface for Broadband Wireless Access Systems
It is a rollup of 802.16h, 802.16j and Std 802.16m
(but excluding the WirelessMAN-Advanced radio interface, which was moved to IEEE Std 802.16.1).
Released on 2012-August-17.

Current

802.16.1-2012

IEEE Standard for WirelessMAN-Advanced Air Interface for Broadband Wireless Access Systems
Released on 2012-September-07.

Current

802.16p-2012

IEEE Standard for Air Interface for Broadband Wireless Access SystemsAmendment 1: Enhancements to Support Machine-to-Machine Applications
Released on 2012-October-08.

Current

802.16.1b-2012

IEEE Standard for WirelessMAN-Advanced Air Interface for Broadband Wireless Access SystemsAmendment 1: Enhancements to Support Machine-to-Machine Applications
Released on 2012-October-10.

The 802.16 standard essentially standardizes two aspects of the air interface – the physical layer (PHY) and the media access control (MAC) layer. This section provides an overview of the technology employed in these two layers in the mobile 802.16e specification.

802.16e uses scalable OFDMA to carry data, supporting channel bandwidths of between 1.25 MHz and 20 MHz, with up to 2048 subcarriers. It supports adaptive modulation and coding, so that in conditions of good signal, a highly efficient 64 QAM coding scheme is used, whereas when the signal is poorer, a more robust BPSK coding mechanism is used. In intermediate conditions, 16 QAM and QPSK can also be employed. Other PHY features include support for multiple-input multiple-output (MIMO) antennas in order to provide good non-line-of-sight propagation (NLOS) characteristics (or higher bandwidth) and hybrid automatic repeat request (HARQ) for good error correction performance.

Although the standards allow operation in any band from 2 to 66 GHz, mobile operation is best in the lower bands which are also the most crowded, and therefore most expensive.[3]

The 802.16 MAC describes a number of Convergence Sublayers which describe how wireline technologies such as Ethernet, Asynchronous Transfer Mode (ATM) and Internet Protocol (IP) are encapsulated on the air interface, and how data is classified, etc. It also describes how secure communications are delivered, by using secure key exchange during authentication, and encryption using Advanced Encryption Standard (AES) or Data Encryption Standard (DES) during data transfer. Further features of the MAC layer include power saving mechanisms (using sleep mode and idle mode) and handover mechanisms.

A key feature of 802.16 is that it is a connection-oriented technology. The subscriber station (SS) cannot transmit data until it has been allocated a channel by the base station (BS). This allows 802.16e to provide strong support for quality of service (QoS).

Quality of service (QoS) in 802.16e is supported by allocating each connection between the SS and the BS (called a service flow in 802.16 terminology) to a specific QoS class. In 802.16e, there are 5 QoS classes:

Data streams for which no minimum service level is required and therefore may be handled on a space-available basis

HTTP

The BS and the SS use a service flow with an appropriate QoS class (plus other parameters, such as bandwidth and delay) to ensure that application data receives QoS treatment appropriate to the application.

Because the IEEE only sets specifications but does not test equipment for compliance with them, the WiMAX Forum runs a certification program wherein members pay for certification. WiMAX certification by this group is intended to guarantee compliance with the standard and interoperability with equipment from other manufacturers. The mission of the Forum is to promote and certify compatibility and interoperability of broadband wireless products.